title: Anatomical and computed tomographic analysis of the transcochlear and endoscopic transclival approaches to the petroclival region.
abstract: OBJECTIVE
  Advances in the field of skull base surgery aim to maximize anatomical exposure while minimizing patient morbidity. The petroclival region of the skull base presents numerous challenges for surgical access due to the complex anatomy. The transcochlear approach to the region provides adequate access; however, the resection involved sacrifices hearing and results in at least a grade 3 facial palsy. An endoscopic endonasal approach could potentially avoid negative patient outcomes while providing a desirable surgical window in a select patient population.
  
  
  METHODS
  Cadaveric study.
  
  
  METHODS
  Endoscopic access to the petroclival region was achieved through an endonasal approach. For comparison, a transcochlear approach to the clivus was performed. Different facets of the dissections, such as bone removal volume and exposed surface area, were computed using computed tomography analysis.
  
  
  RESULTS
  The endoscopic endonasal approach provided a sufficient corridor to the petroclival region with significantly less bone removal and nearly equivalent exposure of the surgical target, thus facilitating the identification of the relevant anatomy. The lateral approach allowed for better exposure from a posterolateral direction until the inferior petrosal sinus; however, the endonasal approach avoided labyrinthine/cochlear destruction and facial nerve manipulation while providing an anteromedial viewpoint. The endonasal approach also avoided external incisions and cosmetic deficits. The endonasal approach required significant sinonasal resection.
  
  
  CONCLUSIONS
  Endoscopic access to the petroclival region is a feasible approach. It potentially avoids hearing loss, facial nerve manipulation, and cosmetic damage.
authors.affiliation: Department of Otolaryngology, Center for Cranial Base Surgery, Georgia Regents University, Augusta, Georgia, U.S.A.
authors.forename: Eric
authors.initials: E
authors.lastname: Mason
authors.forename: Jason
authors.initials: J
authors.lastname: Van Rompaey
authors.forename: Ricardo
authors.initials: R
authors.lastname: Carrau
authors.forename: Benedict
authors.initials: B
authors.lastname: Panizza
authors.forename: C Arturo
authors.initials: CA
authors.lastname: Solares
mesh_terms: D002102:Cadaver; D003051:Cochlea / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D004210:Dissection; D004724:Endoscopy / Q000379:methods; D020220:Facial Nerve Injuries / Q000517:prevention & control; D034381:Hearing Loss / Q000517:prevention & control; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009296:Nasal Cavity / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods; D010579:Petrous Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D011183:Postoperative Complications / Q000517:prevention & control; D019291:Skull Base / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Cranial base; cerebellopontine angle; facial nerve; petroclival; skull base; skull base endoscopic